Typewriting machine



Dea-28,1943. W, A DOBSQN i 2,337,593

TYPEWRITING MACHINE Filed April 2, 1941 3 Sheets-Sheet 1 mvENTolz JWM/mf 2 005504/ i ATTOENEY W. A. DOBSON TYPEWRITING MACHINE Filed April 2, 1941 i 3 Sheets-Sheet 2` INVEN-roR W/ z 4M r2 00550# BY a ATTORNEY Patented Dec. 28, 1943 UNITED STATES TYPEWRITING William A. Dobson, Wethersfield, Conn., as signor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application April 2, 1941,` Serial No. 386,510

Claims.

This invention relates to carriage-stop mechanisms for typewriting machines, and more particularly to margin-gaging mechanisms having provision for key setting of margin-dening stops selectively at substantially any letter-space increment of carriage travel.

`The present invention is in the nature of an improvement over the key-settable margin-stop mechanism shown and described in my copending application Serial No. 376,045, led January 27, 1941, now Patent No. 2,328,376, issued August 3l, 1943. The carriage-stop mechanism therein described provides a series of letter-spaced, uniform stops settable individually by key operation of a stop setter, the stops being selectable by positioning the carriage. A single counterstop is provided with which any two set stops may cooperate to limit carriage travel in either direction to Within a normal line length established by the particular stops selected. Any one stop being set may be adapted to define either the left-hand or right-hand margin of a typed line, provision being made to render the counterstop momentarily inelective during setting of the stop, subsequent carriage movement in an appropriate direction being eiective to release the counterstop at the proper side of the set stop. The carriagestop mechanism also provides for margin release `to permit typing beyond either margin defined 4by the set stops. Upon operation of the marginrelease key, the normally effective counterstop is Withdrawn out of the path vof the set stops and so held by latching means releasable automatically when the carriage is returned to within the limits of the normal typing line.

The present invention is directed to provide an improved margin-release mechanism by Ywhich operation'of the margin release is prevented unless the carriage is positioned at either margin, to thereby forestall unintentional margin release which would render the mechanism temporarily ineffective for margin-gaging purposes.

Another object of the invention is to provide a margin-gaging mechanism having a locking device associated with the normally eective counterstop adapted to be retracted to effect margin release, the locking device being normally effective to obstruct full retraction of the counterstop and being rendered ineffective when the latter is engaged by either of the margin-delining stops.

A further object is to provide a key-settable margin-gaging mechanism having a device for adapting any selected stop to function selectively either as a rightor left-hand margin stop, by appropriate carriage movement after stop setting, the device being also adapted to lock the retract- :able counterstop in its normal projected position unless rendered ineffective by cooperation of `the margin-gaging stops therewith.

Other objects and advantages will hereinafter appear.

In the drawings: y

Figure lis a transverse sectional view taken on a fore-and-aft plane of a typewriter embodying the margin-gaging mechanism of the invention,

Figure 2 is a fragmentary front, elevational view of the margin-gaging mechanism in its normal condition for gaging `the 'line ends of a typing line,

Figure 3 is a transverse section through the mechanism, taken 0D a line 3-3 o f Figure '2,

Figure 4 is an elevational view similar toV Figure 2 vbut showingv the mehnism operated ,for margin release preparatory to typing vbeyond the normal line ends,

Figure his a view similar tov Figure q2 `but showing the condition of the mehanism upon an attempted operation of` margin release with the carriage in an arbitrary position intermediate the normal line-ends defined'by the set stops,

Figure 6 shows the mechanism conditioned for margin release in that the carriage'isat line-start position as gaged` by the left-hand margin stop,

Figure 7 isa view similar to Figure `6 but showing the mechanism conditioned for margin release with the carriage at the typing-'lne-end position as eased by the .rightfharid Stop, and

Figures 8 and Sare views illustratingsuccessive intermediate stages in the operationoi' the mechanism to insti-tute margin` release from the Figure 7 condition.

The general operation of A,the typewriting machine, insofar as it `pertains .t0 the use and ad- Vantages 0f the present intention, will be described in reference to` Figure `1. A carriage IU supports a. platen `l I and ismounted by traclways l2 `for line typing and return. travel on a main frame I3 of the machine. .A spring drum .lil actuates the carriage in line-,typing direction under control of .a letter-feed escapement mechanism l5 which includes an escapement Wheel I6 geared to a rack il on the carriage bya pinion L8. 'Ihe typing instrumentalities may be of any known kind, including `type bars 2 0 that are actuatable to strike against the platen. Il by type keys, not shown. The eseapementmechanism is operated to letter feed the .carriage at each imprint ef a type by vengagement Aof 4the type bars 20 with a universal bar 21, in the usual-manner. In consequence of each type-key Operation, the carriage is advanced step by stepin letter-space intervals to type the characters along@ .typing line., Upon completion of which, the carriage is manually returned to line-start position.

The normal line ends-of carriage travelyare de iinedby the lcooperation ofcertain set steps on .the 4carriage with Aa countertop Qn :the main frame. The `stop organization includes a rack bar 22 on the carriage supporting a series of stops 23 arranged at letter-spaced intervals Each stop is settable selectively from an ineffective position to an operative position at which the stop may engage the counterstop. A detent spring 24 held on the rack bar 22 coacts with each of the stops.

23 to yieldably hold same at the selected posioifset arm'3 of the counterstop, holds the latter tion, each stop having a series of detent notches cooperative with the detent spring.

'I'he stops 23, as shown, have three detent notches so that each stop may be set .to a second operative position in which it may function as a tabulator stop, and the stops each have an oifset tab for cooperation with a second counterstop not shown. The stop .organization may thus function in a carriage stop mechanism adapted both for margin gaging and .tabulating,` in accordance with the disclosure of my copending application Serial No.'372,622, filed December 31,

A 1940, now Patent No`.'2,328,375, issued August 31, 1943. Insofar as the present invention is concerned, however, a clear understanding of its'V operation will be had in considering only the fmechanisr'n for margin gaging, including the features of rightand left-hand stop selection and margin release. It will be understood, however, that the invention is adaptable as well to mechanisms intendedV for both margin gaging and tabul'ating. l

v The stop-setting mechanism is operable by a key to selectively set any of the stops 23 positioned opposite a stop setter 25 by appropriately ylocating the carriage IQ at the desired letter space in itsrange of travel.' Ais'positioned laterally of the main frame i3 at a prescribed point in Xed relation to the printyingpoint of the typewriter. v'the printing pointmay serve as an indicator of The stop setter 25 The type guide at the stop setting point to assist the typist in locating the carriage at the desired letter spaces at which the margins are to be set. The stop setter 25 is mounted for" vertical reciprocation on a bracket plate 2t which may form part of the'main frame of the machine, and has its lower fend flexibly connected to an arm 2l held on a shaft 28 which has a second arm4 29 secured thereto. Afstop setting key 3l! is carried on a ,lever 3l fulcrumed at 32 on the main frame and connected by a'. link 33 to said arm 29. The key 3U is so mounted on the lever as to be selectively operable to make effective either of two limiting means which determine whether a stop 23 will be 'set halfway for 'tabulating or full way for margin gaging. 'When the key 39 is operated to the position'shown in phantom in Figure 1, the stop 'setter is moved through a stroke suflicient to set the stop to its effective position for margin 'gaging The stop setter 25 and its operating train to the key 33 are-restored to inactive po- [sition by a spring 3d. A key-operable stop restorer, not shown, may be provided to restore `the set stops to ineffective position on the rack 22l when a new stop selection is desired.

The mentioned counterstop cooperable with the set stops tov arrest carriage travel atprescribed margins, is indicated at 35, see Figures 2 and 3. For purposes hereinafter manifest, the

1 38 secured vto the bracket plate 25. A yoke plate 39, also secured to said bracket plate, straddles the counterstop 35 and associated elements, and carries a right-hand stop lug 4i) and a left-hand stop lug 4| which limit the swinging movement of the counterstop. A spring 42 anchored on plate 39 yieldably holds the counterstop in its normal raised position and, being active on an normally in a rightward position against the lug 4U. In its normal position, the counterstop has its stop-engaging portion just to the right of the point at which the stops are set, see Figure 2.

The counterstop 35 is swingable to either of two positions, dened by the lugs MJ and l, see Figures 6 and 7, in order that the counterstop may arrest a set stop 23, whether serving for rightor left-hand margin gaging, at the same position, which position corresponds with that at which the stops are set by the stop setter 25. It may be here noted in reference to Figure 6, that in arresting the carriage at line-start position, the left-hand stop drops back a fractional letter spaceY after engaging the counterstop. This drop-back, in varying extents, is usual in fmargin-gaging mechanisms, being necessary to allow the letter-feed escapement to again assume control of the carriage after the latter has been actuated in a return run. The position at which the left-hand stop comes to rest, as shown in Figure 6, corresponds, however, with that at which the stops are set. As shown in Figure '1, the right-hand stop is also arrested at said position upon banking against the counterstop, the stop lug il being arranged to so arrest the said carriage stop.

While the lateral displacement of the counterstop 535, as described, is primarily intendedl to afford corresponding arrest positions for both the rightand left-hand stops, the leftward swinging of the counterstop, incident to gaging the line end or right-hand margin, may also be employed to aotuate a line-lock device to render the typing instrumentaiities inoperative. For this purpose, a lever 3e, see Figure 1, has an end thereof disposed for engagement by the counterstop 35. A block lll carried on said lever is adapted to obstruct operation of the letter-feed escapement mechanism l5 when the counterstop is swung to the Figure 7 position. In blocking the escapement, the universal bar 2l is rendered inoperative and the type bars 2@ are thus stopped before striking the platen. When the counterstop assumes its normal rightward position, a spring, not shown, restores the lever 35 to normal position at which the block il is clear of the escapement mechanism.

Any one of the stops 23 of the series set for margin gaging may be adapted to function either as a left-hand stop to determine the line-start position, or as a right-hand stop to determine the line-end position of the carriage. The adaptation of a set stop for either function is accomplished, following the setting of the stop, by moving the carriage in an appropriate direction. For this purpose, a buttress lili is pivotally 'mounted on the counterstop 35 and is arranged to overlap the stop-engaging portion thereof, extending to the left beyond said portion so as to project into the station at which the stops are set. The top edge of the buttress is arcuate on a radius from its pivotal center so as to clear the stop rack'22 in all angular positions of the buttress. The buttress is yieldably held in normal position by a spring interposed between a lower arm of the buttress and the counterstop, Spring 45 'acentos urges the buttress to rotate counterclockwse; as viewedin Figure 2, to its normali position defined b-y 9,;lug iii of the buttress engaged with. an inner edge of the counterstop.

It will 4be apparent that when setting the stops 23L for margin gaging, none of said. stops are engaged with the counterstop and the latter is, therefore, in its normal upright position, Figure 2, held by spring i2 against the stop lug dii'. As one of the stop-s 23 is set bythe actuation of the stopsetter 35, the lower end ofthe stop engages the buttress fifi and` presses the counterstop downward to a position out of the path of the set carriage stops, against the tension of spring d2 which still urges the counterstop upward. If the set stop is intended for right-hand margin gaging, the carriage is then moved to the right; during which the stop, moving with the carriage and riding along the top edge of the buttress or swinging the buttress with it, travels to the right side of the counterstop and'thence oi the buttress so that the counterstop is released and assumes an eiiective position at the left side' of the set stop. W Len it is intended that the set stop function to gage the left margin, the carriage is moved leitward after setting the stop, and the set stop riding along and off the buttress allows the counterstop to be released at the right side oi the set stop. Thereafter, this set stop will cooperate with the counterstop to gage the linestart ,position of the carriage. The stops 23 set for rightand left-hand margin gaging are indicated at Etf and 231, respectively. It may be here noted that the buttiess M, in regard to its stopadapting function just described, is pivotally mounted in order that same may swing out of the way when the carriage is banked at line-start position, see Figure 6, that is, in order that the left-hand stop 231 may directly engage the counterstop. By following the procedure described, a stop 23 is set for margin gaging adjacent each end oi the carriage, the'two stops 23 and 231 defining a line-typing zone, into which zoneV the counterstcp 3.6 projects for interception of the margin-gaging stops moving with the carriage in either direction. This feature of the mechanism by which a set stop may be adapted for either right or left margin gaging selectively, forms the subject matter of my copendi'ng application Serial No. 376,045, now Patent No. 2,328,- 376.

The mechanism is adapted for margin release; being operable to retractn the counterstop out of the carriage stop path, to allow the' carriage to be moved outside the normal line-typing zone for typing beyond either prescribed margin. It will be observed that when margin release is desired, the carriage usually has been banked Vat one of the margins and, therefore, the'carriage stop defining that margin is engaged with the counterstop. The mechanism is thus conditioned as shown in either Figures 6 orl7, depending on which margin has been reached. It will also be observed that when the carriage is banked at line-end position, Figure 7, the carriage stop ESI has swung the counterstop over against the lug di. From either the Figure 6 or Figure 7 position, the counterstop 35i is retracted to institute margin release, by pressing a margin-release key 58, Figure 1. This key is connected by a push rod 49 to an arm 66 of a rockable member l which has a second arm 52 eXibly connected to the lower end of counterstop 35, being en- Figures 2, 3, and 4, to hold4 the counterst'op/retracted during the typing beyond either margine said latching device being released by return of the carriage to its normal line-typing zone, thereby automatically restoring the mechanism for its normal margin-gaging function.v A resilient latch Vmember 54 is mounted for pivotal and endwise' movement by a stud 55 on the latch member, engaged in a vertically elongate slot 56 in theV yoke plate 39. A tension spring 5l yieldably holds the latchrnember down with the stud 55 bottoming in the slot. The spring is arranged to exert its force on the latch member 54 iri a'4 substantially perpendicular line from the center of stud 55 so as to yieldably hold the latch' member in a normally upright position, The lower end of the latch member is inciined toward the counterstop to provide a bevel 56, see Figure 3i Asthe counterstop is retracted, a catch 65 thereon cooperating with the bevel 56, eXes the la'tcl 5i outwardly `until the catch @e is engaged under the lower end oi the latch. Wl'ienthe counter-1 stop is retracted from the Figure position upon operation of the margiii-reiease key i6, the counterstop moves downwardly until its catch GU: is engaged under the latch, after which the release key 43 is released. The counterstop,under influence of its spring d2, then starts back toward its normal projected position, carrying with it the latch member 517i against the tension of` its spring 5`=',-until stud engages the upper end of slot 55; Under this condition, the counter-` stop is still held retracted but a 'nger Si ofi the' latch member Efi is projected into the carriage"- stop path. This same action takes place' when the counterstop is retracted from the Figure-7 position, except that in this instance the counterstop assumes the upright position only after riding off the carriage stop, and thereafter continues downwardly until the lat-ching taires place; In either instance, after the release key 6 has been depressed and then released, the counter stop and latch assume the condition showny in Figure Ll, and the carriage stop is beyond the counterstop, allowing carriage travel beyond the margin. To complete margin release from the Figure 6 position, the carriage is moved right- Ward before the release key is freed. In this way, the' carriage stop 231 is brought to the right of the counterstop before the latch iinger 6i is-ad'- vanced to effective position. However, when margin release from the Figure 7 position is instituted, the resultant rightward swinging orthe counterstop automatically positions the carriage stop 23r to the right thereof in readiness for typing beyond the right-hand margin or lineV end'.

When the carriage is restored to its normal line-typing zone from beyond either margin, the carriage stop 23 traveling with the carriage, engages the latch linger 6l and trips the latch 54 thereby automatically restoring the counterstop to its normal effective position in the path of and between the set carriage stops 23?, 2531. vThe margin-release mechanism, including the fea'- tures of automatic restoration, as just described', forms the subject matter of my copending appli; cation Serial No. 376,646, filed January 27, i941', now Patent No. 2,328,377, issued August 3l, 1943'. As aforeindicated, the present invention is directed to provide certain improvements in the margin-release mechanism of my copending application Serial No. 376,045, Patent No. 2,328,377 by which operation of said mechanism is prevented'unless the carriage is banked at either margin; that is, unless either of the stops'ZSr or`A 231 is engaged with the counterstop; Vthereby to forestall unintentional margin release which would render the margin-gaging mechanism temporarily ineffective. The improvements herein also relate to my copending application Serial No. 376,045, now Patent No. 2,328,376, in that the member or buttress 45. by which rightand lefthand stop Vselection is aorded, also constitutes part of the means by which the unintentional margin-release operation is forestalled. Y

In view of its further purpose in the Vpresent invention, the buttress fill may be regarded as a locking member in that it serves to lock the counterstop projected when the latter is free of the carriage stops. Accordingly, member 44 carries an abutment or barrier 62 which, in the normal position of member 44, is adapted to engage the stop dil when an attempt is made to operate the margin release with the carriage positioned intermediate the margins. Under such conditions, when the release key 48 is pressed, see Figure 5, the abutment moves bodily with the counterstop as the latter is initially retracted, and engages lug t. Upon release of key 48, spring i2 merely returns the counterstop to itsv normal position, see Figure 2.

'Ihe locking member dii, however, is swung to unlocked position when either of the carriage stops 22'r and 231 is engaged with the counterstop; that is, when the carriage is arrested at either margin. Carriage arrest at the left-hand margin produces the condition shown in Figure 6 in which stop 231, engaging the wing of locking member 41%, has rotated same against the tension of its spring Q5 to a position in which the abutment 62 is clear of lug 40. Thus, the counterstop 35 is unlocked and may be fully retracted to the margin-release position shown in Figure 4, upon operation of the margin-release key-4S. It will, of course, be noted that as soon as the counterstop 35 is fully retracted, the locking member 45, riding oli the carriage stop 231, snaps back to its normal position under influence of spring t5, so that when the counterstop is again released, the locking member 44 is in position to again prevent margin release except under the conditions stated.

It may be here noted that, with the mechanism in normal condition, Figure 2, the abutment 62 of member de is spaced from the lug e0 a distance ample to allow the counterstop 35 to be retracted out of the path of stops 23, but not sufficient to let the counterstop be latched in retracted position by the latch 54. This initial retraction of the counterstop, as gaged by the spacing of abutment 52 from lug 40, is necessary in stop setting, t0 allow the counterstop to be retracted out of the stop path, so that when the carriage is subsequently moved the set stop may pass over the counterstop to a position to the right thereof, according to the function of member d as previously described.

The operation of the mechanism for unlocking the counterstop from the condition assumed in gaging the right-hand margin or line-end position of the carriage, is shown best in Figures 7, 8 and 9. The locking member i4 has an inclined arm 6d which, in the leftwardly displaced position of the counterstop, engages with a prong 65 von the yoke plate 3i). Said arm is offset forwardly from the plane of member 44 so as to maintain contact with the prong. The prong 55 terminates just in front of the body portion of member @d to allow the latter to assume the Figure 7 position.` As the margin-release key 48 is pressed, counterstop 35 is initially retracted to the position shown in Figure 8 at which the counterstop is about to ride 01T carriage stop 23T. While the counterstop moves to this position, the engagement of arm 64 with prong E5 is maintained, the displacement of the lockingV member pivot causing member 44 to rotate to such position that the abutment 62 is below the stop 40. Thus, as the counterstop leaves the carriage stop, with the result that the counterstop is allowed to swing rightward as shown in Figure 9, the abutment 62 is well below lug lll so that its locking engagement therewith is prevented, even though spring 45 urges member 44 to its normal locking position. Thereafter, the counterstop is fully retracted and is so latched, thereby assuming the position shown in Figure 4 with member 44 restored in readiness for its locking function when the counterstop is again released.

What is claimed is:

1. In a typewriter having a frame and a carriage movable in opposite directions on the frame; a stop and a counterstop mounted one on the frame and the other on the carriage, the counterstop being engageable with the stop to halt carriage movement in one direction; means to move the counterstop to a holding position clear of the stop, to release the carriage for additional movement; means to releasably hold the counterstop so moved; means including a barrier to prevent movement of the counterstop to said holding position; and means, rendered effective upon stop and counterstop engagement to disable said preventing means.

2. In a typewriter having a frame and a travelable carriage, in combination, a stop and a counterstop mounted one on the frame and the other on the carriage, said counterstop being movable between a position engageable with said stop and a retracted, latching position clear of said stop, means for moving the counterstop to said retracted, latching position, latching means to releasably hold the counterstop retracted when moved to the latching position, means to obstruct counterstop retraction to latching position, and means, operable by said stop, to render the last-said means ineiective.

3. In a typewriter having a frame and a travelable carriage, in combination, a stop and a counterstop mounted one on the frame and the other` on the carriage, said counterstop being movable between a position engageable with said stop and a retracted, latching position clear of said stop, means for moving the counterstop to said retracted, latching position, latching means to releasably hold the counterstop retracted when moved to the latching position, and a movable locking member normally obstructing counterstop retraction to latching position but engageable and movable by said stop to allow counterstop retraction.

4. In a typewriter having a frame and a travelable carriage, in combination, a stop and a. counterstop mounted one on the frame and the other on the carriage, said counterstop being movable between a position engageable with said stop and a retracted, latching position clear of said stop, means for moving the counterstop to said retracted, latching position, latching means to releasably hold the counterstop retracted when moved to the latching position, and a member movably carried on said counterstop and obstructing counterstop retraction to latching position, said member being movable by said stop,

when approaching the counterstop, to a position allowing counterstop retraction.

5. In a ltypewriter having a frame and a travelable carriage, in combination, a stop and a counterstop mounted one on the frame and the other on the carriage, said counterstop being movable between a position engageable with said stop and a retracted, latching position clear of said stop, means for moving the counterstop to said retracted, latching position, latching means to releasably hold the counterstop retracted when moved to the latching position, a member mounted on said counterstop for movement between a position obstructing counterstop retraction to latching position and a second position allowing said retraction, and means urging said member to obstructing position, said member being engageable and movable by said stop to said seco-nd position.

6. In a typewriter having a frame and a travelable carriage, in combination; a series of stops arranged at letter-space intervals on the carriage for setting to effective position; key-operable means for setting any one of said stops, positioned by carriage movement, at a stop-setting station; a counterstop on the frame adjacent said station, mounted for movement between an effective position engageable With the set stop and a retracted, latching po-sition clear of the set stop; means urging the counterstop to the effective position; means for retracting the counterstop to the latching position; latching means to releasably hold the counterstop retracted when moved to latching position; and a member pivoted on said counterstop and yieldably held in a position in which a part of said member is disposed in said stop-setting station, said member having an abutment obstructing counterstop retraction to latching position and being adapted to be engaged and moved pivotally by a set stop during carriage travel, to withdraw the abutment and thus permit said counterstop retraction.

7. In a typewriter having a frame and a travelable carriage, in combination; a series of stops arranged at letter-space intervals on the carriage for setting to eective position; key-operable means for setting any one of said stops, positioned by carriage movement, at a stop-setting station; a counterstop on the frame adjacent said station, normally urged to effective position in the path of the set stop; a member pivoted on said counterstop and yieldably held in a normal position in which a part of said member is disposed in said stop-setting station for engagement by a stop being set, to thereby initially retract and so hold the counterstop in setting the stop, until a subsequent carriage movement moves the set stop out of said station, thereby releasing the counterstop at one side of the set stop; marginrelease mechanism including means for retracting the counterstop beyond initially retracted position and clear of the stop and means to releasably hold the counterstop so retracted; said member having an abutment normally obstructing counterstop retraction beyond initially retracted position, said member being adapted to be engaged and moved pivotally by the set stop during carriage travel to withdraw the abutment and thus permit counterstop retraction and latching for margin release.

8. In a typewriter having a frame and a reciprocatory carriage, in combination; a series of selectively key-settable stops on the carriage, any two of said stops that are set being adapted t define the normal line ends of carriage travel; a counterstop mounted on the frame for shifting in the direction of carriage travel between two positions, said counterstop being also movable between an effective position engageable with the set stops and a retracted, latching position clear of said stops; means for retracting the counterstop to said latching position; latching means to releasably hold the counterstop retracted when moved to the latching position; a locking member movably mounted on the counterstop for movement bodily therewith and obstructing counterstop retraction to latching position; and means, operative upon counterstop engagement by one or the other of the set stops, depending on the direction of carriage travel, to render said locking member ineffective in the corresponding, shifted position oi the counterstop.

9. In a typewriter having a frame and a reciprocatory carriage, in combination; a series of selectively key-settable stops on the carriage, any two of said stops that are set being adapted to denne the normal line ends of carriage travel; a counterstop mounted on the frame for shifting in the direction of carriage travel from a normal position to a displaced position; said counterstop being also movable between an effective position engageable with the set stops and a retracted, latching position clear of said stops; means yieldably holding the counterstop in said eiective position; means for moving the counterstop to said retracted, latching position; latching means to releasably hold the counterstop retracted when moved to the latching position; and a member pivoted on said counterstop and having an abutment which, in the normal position of the counterstop, obstructs counterstop retraction to the latching position; said member being adapted, in the normal position of the counterstop,.for engagement by a set stop to Withdraw the abutment; and said member having means which, in the displaced position of the counterstop, coacts with the frame to swing said member during subsequent counterstop retraction and thereby render said abutment ineiective.

l0. In a typewriter having a frame and a reciprocatory carriage, in combination, a series of stops arranged at letter-space intervals on the carriage for setting to effective position, key-operable means for setting any one of said stops, positioned by carriage movement, at a stop-setting station, a counterstop mounted on the frame for retraction out of the stop path and for shifting in the direction of carriage travel from a normal position just to the right of said station to a displaced position just to the left of said station, means yieldably holding the counterstop in said normal position and in the stop path, marginrelease mechanism including means for retracting the counterstop to a holding position out of said path and means to releasably hold the counterstop so retracted, and a member pivoted on said counterstop and yieldably held in a normal position in which said member is disposed in said station, said member having an abutment normally obstructing counterstop retraction to said holding position, said member being adapted, in the normal counterstop position, for engagement by a set stop to withdraw the abutment, said membel1 having a portion which, in the displaced counterstop position, co-acts with the frame to swing said member and thus render the abutment ineiective during subsequent counterstop retraction.

WILLIAM A. DOBSON. 

